Here are 3 different brackets....the first gen is the only bracket that uses a long 5/16" bolt with either a nylock nut or a top lock nut, depending on my supply at the time. The bolt is long because it goes through a boxed cross member unlike the 2nd gen Taco & Tundra. The 1st gen (95.5-04) bracket works on 5 and 6 lug trucks.
The second gen Taco and Tundra use fatter 1/2" bolts up top, and the same goes for the nut, nylock or top lock, depending on my supply.
Also, depending on whether the bracket is a 1.5" drop, or a 2" drop, will determine the bottom bolts. The 1.5" brackets use metric bolts that replace the stock ones to bolt the carrier cage to the bracket and the bracket to the frame. The 2" brackets use shorter standard bolts below to attach the carrier cage to the bracket, and the OEM ones get reused to attach the bracket to the frame.
left to right...2nd gen Taco, Tundra, and 1st gen Taco. (all 1.5" drop)
2" style...you reuse your OEM bolts to attach the bracket to the frame. 2nd gen Taco pictured. (This was actually a 2-3/8" drop for DOM, Tacoridinhigh. He said it helped immensely)